Optical recording storage involves laser technique to record data in an optical recoding media. Currently, organic dyes are typically utilized to form a recording layer on optical recording discs. After the implementation of burning process on an optical recording disc, the organic dye of the recording layer would be degradation or deformation due to irradiating light beam on the disc by a laser having a constant burning power. The procedure will cause reflective index difference between the burned region and the non-burned region. Consequently, data stored in the optical disc could be read by a laser with an appropriate power by utilizing the difference of reflective indexes.
Because the range of the light wavelength absorbed by the organic dyes is narrow, only few specific organic dyes can be used at a specific wavelength range. According to current blue-ray recordable media, the wavelength of a laser light is short (405 nm). Therefore, the potential organic dyes species utilized in the blue-ray recordable media are few. Furthermore, it is because that the gauges of the substrate guiding track of the blue-ray recordable media are narrow, thus the organic dye is unlikely to be coated on the substrate uniformly. Therefore, in recent years, some researches announce to replace the organic dyes by inorganic materials, such as conductor (metal) or semiconductor, to form the recording layer of the recordable discs.